unable to install from aur

[Linux for blind general discussion]

Whenever I try and install from the archlinux user repository and the pacckage requires a gpg signiture, it fails.
This is the contents of my ~/.gnupg/gpg.conf:
charset utf-8
require-cross-certification
no-escape-from-lines
no-mangle-dos-filenames
personal-digest-preferences SHA512
cert-digest-algo SHA512
use-agent
default-preference-list SHA512 SHA384 SHA256 SHA224 AES256 AES192 AES CAST5 ZLIB BZIP2 ZIP Uncompressed
keyserver wwwkeys.pgp.net
keyserver hkp://pool.sks-keyservers.net
keyserver pgp.zdv.uni-mainz.de
keyserver hkp://keys.gnupg.net
key-server https://sks-keyservers.net
keyserver-options auto-key-retrieve

I can install with pacman just fine. Just not from aur.
What can I do to debug this?